Project Summary/Abstract - Core B: The goal of the Biomarkers Core (Core B) is to support Projects 1-3 and Core C in this P01 application by providing bioanalytical support for a broad range of analytical and biochemical assays that address the fundamental redox biology of the production of O2?-/H2O2, hydroperoxide metabolism, and processing of redox active metal ions relevant to the study of pharmacological ascorbate (P-AscH-) in preclinical models and clinical trials. Core B will provide validated reagents, e.g. stock solutions of key reagents, standards, Seahorse and EPR analyses, enzymological analyses, ionizing radiation services, and molecular biology reagents, to Projects 1-3. Examples range from our unique, efficient, and cost-effective assays for determining plasma ascorbate concentrations in patient-derived samples (Project 1 and Project 2) as well as assays for ascorbate in the wide variety of samples generated in the proposed preclinical studies (Projects 1-3). Core B has a large repertoire of assays that will examine the basic redox biology of P-AscH-. The leaders of the core have also developed new unique assays and methods that are focused on addressing questions central to the proposed clinical trials in this P01. The leaders have more than 30 years of experience in this field as well as in directing University of Iowa core facilities in the Carver College of Medicine and the Holden Comprehensive Cancer Center. Thus, they are well qualified to lead this core.